| 摘要 |
PURPOSE:To attain stable automatic tracing focus detection by restoring a tracing visual field to the original position after the passage of a prescribed period when a subject relatively goes out to the outside of a photographing surface or a specific area. CONSTITUTION:Ligit reflected from a subject is made incident upon a solid state image pickup element 2 through a lens group 1, its output signal is processed by a signal processing circuit 3 and a color difference signal is inputted to a movement detecting circuit 5 through a trace gate circuit 4 to detect moving direction and moving distance of the subject. The detecting signal is inputted to a gate moving circuit 6, which outputs a signal for moving the position of the trace gate circuit 4, i.e. the position of a tracing vidual field, in accordance with the movement of the subject to be traced to a gate pulse generating circuit 11 and an arithmetic circuit 19. Deciding that the position of the subject on the screen goes out to the outside of a limit area set up by a limit area setting circuit 18, the circuit 19 restores the gate position of the gate circuit 4 to the initial position after the passage of a prescribed period specified by a timer 22 through a pulse generated from the circuit 11. |
